U.S. patent number 10,808,106 [Application Number 15/775,068] was granted by the patent office on 2020-10-20 for saturated triglyceride-containing rubber composition, tires and tire components containing the rubber composition, and related methods.
This patent grant is currently assigned to Bridgestone Americas Tire Operations, LLC. The grantee listed for this patent is Bridgestone Americas Tire Operations, LLC. Invention is credited to Emily W. Demeter, Benjamin C. Galizio.
United States Patent |
10,808,106 |
Galizio , et al. |
October 20, 2020 |
Saturated triglyceride-containing rubber composition, tires and
tire components containing the rubber composition, and related
methods
Abstract
Disclosed herein are rubber compositions containing a saturated
triglyceride component of specified melting point, as well as tires
and tire components containing the rubber composition. Also
disclosed are methods for improving the performance of a tire tread
(such as by improving the wet traction) containing the rubber
composition.
Inventors: |
Galizio; Benjamin C. (Kent,
OH), Demeter; Emily W. (Aiken, SC) |
Applicant: |
Name |
City |
State |
Country |
Type |
Bridgestone Americas Tire Operations, LLC |
Nashville |
TN |
US |
|
|
Assignee: |
Bridgestone Americas Tire
Operations, LLC (Nashville, TN)
|
Family
ID: |
1000005125609 |
Appl.
No.: |
15/775,068 |
Filed: |
October 24, 2016 |
PCT
Filed: |
October 24, 2016 |
PCT No.: |
PCT/US2016/058396 |
371(c)(1),(2),(4) Date: |
May 10, 2018 |
PCT
Pub. No.: |
WO2017/083082 |
PCT
Pub. Date: |
May 18, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
|
US 20180327575 A1 |
Nov 15, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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62253972 |
Nov 11, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60C
1/00 (20130101); C08K 5/11 (20130101); B60C
1/0016 (20130101); C08K 3/013 (20180101); C08L
9/00 (20130101); C08K 5/01 (20130101); C08L
9/06 (20130101); C08K 5/11 (20130101); C08L
9/00 (20130101); C08K 5/11 (20130101); C08L
9/06 (20130101); C08K 5/11 (20130101); C08L
7/00 (20130101); C08K 3/013 (20180101); C08L
9/00 (20130101); C08K 3/013 (20180101); C08L
9/06 (20130101); C08K 3/013 (20180101); C08L
7/00 (20130101); C08K 5/01 (20130101); C08L
9/00 (20130101); C08K 5/01 (20130101); C08L
9/06 (20130101); C08K 5/01 (20130101); C08L
7/00 (20130101); C08L 9/06 (20130101); C08L
9/00 (20130101); C08L 7/00 (20130101); C08K
3/36 (20130101); C08K 3/04 (20130101); C08L
2205/025 (20130101); C08K 3/36 (20130101); C08L
2205/03 (20130101); C08K 3/04 (20130101) |
Current International
Class: |
C08L
9/06 (20060101); B60C 1/00 (20060101); C08L
9/00 (20060101); C08K 5/11 (20060101); C08K
5/01 (20060101); C08K 3/013 (20180101); C08K
3/04 (20060101); C08K 3/36 (20060101) |
Field of
Search: |
;524/313 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0561761 |
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0677548 |
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Oct 1995 |
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EP |
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2028022 |
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Feb 2009 |
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EP |
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2000071711 |
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Mar 2000 |
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JP |
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2007-380623 |
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Nov 2007 |
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JP |
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2007308623 |
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Nov 2007 |
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JP |
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2009-096956 |
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May 2009 |
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JP |
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2010-138272 |
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Jun 2010 |
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JP |
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51-44031 |
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Feb 2013 |
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JP |
|
2015067827 |
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Apr 2015 |
|
JP |
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2009-112220 |
|
Sep 2009 |
|
WO |
|
Other References
JP 2000-071711 A, machine translation, EPO espacenet. (Year: 2000).
cited by examiner .
JP 2015-067827 A, machine translation, EPO espacenet. (Year: 2015).
cited by examiner .
International Preliminary Report on Patentability and Written
Opinion from application PCT/US2016/058396 dated May 15, 2018.
cited by applicant .
International Search Report dated Jan. 26, 2017 from application
PCT/US2016/058396. cited by applicant .
Cargill brochure "Agri-pure product portfolio > vegetable Waxes"
copyright 2014. cited by applicant .
Zambiazi, Rui Carlos et al., "Fatty Acid Composition of Vegetable
Oils and Fats," B. Ceppa, Curitiba, vol. 25, No. 1, pp. 111-120,
Jan./Jun. 2007. cited by applicant .
"Carnauba Wax," 2 pages, prepared at the 51st JEFCA in 1998,
published 1998. cited by applicant .
Garriga, Mariana Ribas, Evaluation of Natural Wax for Green
Packaging Applications, 96 pages, published May 2019. cited by
applicant.
|
Primary Examiner: Chang; Josephine L
Attorney, Agent or Firm: Hooker; Meredith E. Sheaffer; Jenny
L.
Claims
What is claimed is:
1. A tire tread rubber composition, comprising: at least one
conjugated diene-containing polymer or copolymer including at least
one of: styrene-butadiene copolymer, polybutadiene polymer, natural
rubber, or polyisoprene, greater than 30 to 60 phr of a saturated
triglyceride component having a melting point of greater than
40.degree. C. and at least 90% by weight saturated fatty acids in
triglyceride form, 50 to 200 phr of at least one reinforcing filler
including at least one of carbon black or silica, and a cure
package, wherein the rubber composition comprises less than 10 phr
in total of petroleum oil, mineral oil, and plant oil.
2. The tire tread rubber composition of claim 1, wherein the
saturated triglyceride component comprises saturated plant
triglycerides.
3. The tire tread rubber composition of claim 1, wherein the
saturated triglyceride component has a melting point of 60 to about
95.degree. C.
4. The tire tread rubber composition of claim 1, wherein the
saturated triglyceride component comprises at least 95% by weight
saturated fatty acids in triglyceride form.
5. The tire tread rubber composition of claim 1, wherein at least
30% by weight of saturated fatty acids within the saturated
triglyceride component have a chain length of C18 or higher.
6. The tire tread rubber composition of claim 1, wherein at least
50% by weight of saturated fatty acids within the saturated
triglyceride component have a chain length of C18 or higher.
7. A tire tread rubber composition, comprising: at least one
conjugated diene-containing polymer or copolymer including at least
one of: styrene-butadiene copolymer, polybutadiene polymer, natural
rubber, or polyisoprene, 5 to 60 phr of a saturated triglyceride
component having a melting point of greater than 60 to about
95.degree. C. and at least 90% by weight saturated fatty acids in
triglyceride form, 50 to 200 phr of at least one reinforcing filler
including at least one of carbon black or silica, and a cure
package, wherein the rubber composition comprises less than 10 phr
in total of petroleum oil, mineral oil, and plant oil.
8. The tire tread rubber composition of claim 7, wherein the
saturated triglyceride component comprises saturated plant
triglycerides.
9. The tire tread rubber composition of claim 7, wherein the
saturated triglyceride component has a melting point of 65 to about
95.degree. C.
10. The tire tread rubber composition of claim 7, wherein the
saturated triglyceride component has a melting point of greater
than 60 to 80.degree. C.
11. The tire tread rubber composition of claim 7, wherein the
saturated triglyceride component comprises at least 95% by weight
saturated fatty acids in triglyceride form.
12. The tire tread rubber composition of claim 7, wherein at least
30% by weight of saturated fatty acids within the saturated
triglyceride component have a chain length of C18 or higher.
13. The tire tread rubber composition of claim 7, wherein at least
50% by weight of saturated fatty acids within the saturated
triglyceride component have a chain length of C18 or higher.
Description
FIELD
The present application is directed to rubber compositions
containing a saturated triglyceride component, tires and tire
components containing the rubber composition, and related methods
for improving tire performance such as by incorporating the rubber
composition into a tire tread.
BACKGROUND
Rubber compositions used to produce tire components may contain
various ingredients in addition to their majority ingredients which
are generally one or more rubbers in combination with one or more
reinforcing fillers such as carbon black and silica. These various
other ingredients may positively or negatively impact tire
performance properties of the rubber compositions. Measurement of a
rubber composition's dynamic mechanical properties such as storage
modulus (E') and tangent delta can be used to predict tire
performance when the rubber composition is incorporated into a tire
tread. However, improvement across properties is often inconsistent
or unbalanced. The ability to achieve more consistent improvements
in properties is generally desirable but often challenging.
SUMMARY
Disclosed herein are rubber compositions containing a saturated
triglyceride component, as well as tires and tire components
containing the rubber composition. Also disclosed are methods for
improving the performance of a tire tread (such as by improving the
wet traction) containing the rubber composition.
In a first embodiment, a rubber composition for use in a tire
component is disclosed. The rubber composition comprises: at least
one conjugated diene-containing polymer or copolymer, about 1 to
about 60 phr of a saturated triglyceride component having a melting
point of at least 40.degree. C., and about 5 to about 200 phr of at
least one reinforcing filler.
In a second embodiment, a tire comprising at least one component
made from a rubber composition according to the first embodiment is
disclosed.
In a third embodiment, a method for improving the performance
(e.g., the wet traction as measured by tan .delta. at 0.degree. C.)
of a tire tread is disclosed. The method comprises incorporating
about 1 to about 60 phr of a saturated triglyceride component
having a melting point of at least 40.degree. C. into a rubber
composition comprising at least one conjugated diene-containing
polymer or copolymer and 5 to 200 phr of at least one reinforcing
filler.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph showing a plot of E' over a temperature range as
indicated therein for Examples 1-4 with the X axis showing
temperature in .degree. C. and the Y axis showing values of E'
(with lower values of E' appearing lower on the Y axis).
FIG. 2 is a graph showing a plot of tan .delta. over a temperature
range as indicated therein for Examples 1-4 with the X axis showing
temperature in .degree. C. and the Y axis showing values of tan
.delta. (with lower values of tan .delta. appearing lower on the Y
axis).
DETAILED DESCRIPTION
Disclosed herein are rubber compositions containing a saturated
triglyceride component, as well as tires and tire components
containing the rubber composition. Also disclosed are methods for
improving the performance of a tire tread (such as by improving the
wet traction) containing the rubber composition.
In a first embodiment, a rubber composition for use in a tire
component is disclosed. The rubber composition comprises: at least
one conjugated diene-containing polymer or copolymer, about 1 to
about 60 phr of a saturated triglyceride component having a melting
point of at least 40.degree. C., and about 5 to about 200 phr of at
least one reinforcing filler.
In a second embodiment, a tire comprising at least one component
made from a rubber composition according to the first embodiment is
disclosed.
In a third embodiment, a method for improving the performance
(e.g., the wet traction as measured by tan .delta. at 0.degree. C.)
of a tire tread is disclosed. The method comprises incorporating
about 1 to about 60 phr of a saturated triglyceride component
having a melting point of at least 40.degree. C. into a rubber
composition comprising at least one conjugated diene-containing
polymer or copolymer and 5 to 200 phr of at least one reinforcing
filler.
Definitions
As used herein, the term "natural rubber" means naturally occurring
rubber such as can be harvested from sources such as Hevea rubber
trees and non-Hevea sources (e.g., guayule shrubs and dandelions
such as TKS). In other words, the term "natural rubber" should be
construed so as to exclude synthetic polyisoprene.
As used herein, the term "phr" means parts per one hundred parts
rubber. The 100 parts rubber can be understood as referring to 100
parts of the at least one conjugated diene-containing polymer or
copolymer.
As used herein the term "polyisoprene" means synthetic
polyisoprene. In other words, the term is used to indicate a
polymer that is manufactured from isoprene monomers, and should not
be construed as including naturally occurring rubber (e.g., Hevea
natural rubber, guayule-sourced natural rubber, or
dandelion-sourced natural rubber). However, the term polyisoprene
should be construed as including polyisoprenes manufactured from
natural sources of isoprene monomer.
As used herein, the phrase "saturated triglyceride component"
refers to an ingredient containing primarily saturated fatty
acid(s) (as opposed to mono- or polyunsaturated fatty acids) in
triglyceride form (i.e., three fatty acids bound to a glycerol
backbone as opposed to free fatty acids, monoglycerides or
diglycerides).
Conjugated Diene-Containing Polymer or Copolymer
As discussed above, according to the first-third embodiments
disclosed herein, the rubber composition includes at least one
conjugated diene-containing polymer or copolymer. In certain
embodiments of the first-third embodiments disclosed herein, the
rubber composition can be understood as including 100 parts (or 100
phr) of at least one conjugated diene-containing polymer or
copolymer. As used herein, the phrase "conjugated diene-containing
polymer or copolymer" refers to a conjugated diene-containing
polymer, copolymer, or combination thereof (i.e., more than one
polymer, more than one copolymer, one polymer and one copolymer,
more than one polymer and one copolymer, more than one copolymer
and one polymer, or more than one copolymer and more than one
polymer). In accordance with certain embodiments according to the
first-third embodiments, the at least one conjugated
diene-containing polymer or copolymer is derived from, for example,
the polymerization of one or more of the following conjugated diene
monomers: 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene,
2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene,
2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene,
4-methyl-1,3-pentadiene, 2,4-hexadiene, 1,3-cyclopentadiene,
1,3-cyclohexadiene, 1,3-cycloheptadiene, and 1,3-cyclooctadiene,
and derivatives thereof. It should be understood that mixtures of
two or more conjugated diene monomers may be utilized in certain
embodiments of the first-third embodiments. In certain embodiments
of the first-third embodiments disclosed herein, the at least one
conjugated diene-containing polymer or copolymer includes at least
one conjugated diene monomer in combination with at least one vinyl
aromatic monomer. In accordance with certain embodiments of the
first-third embodiments disclosed herein, the at least one
conjugated diene-containing polymer or copolymer is a copolymer
which results from the polymerization of not only at least one of
the foregoing diene monomers but one or more of the following vinyl
aromatic monomers: styrene, alpha-methyl styrene, p-methylstyrene,
o-methylstyrene, p-butylstyrene, vinylnaphthalene,
p-tertbutylstyrene, 4-vinylbiphenyl, 4-vinylbenzocyclobutene,
2-vinylnaphthalene, 9-vinylanthracene, 4-vinylanisole, or vinyl
catechol. In certain embodiments of the first-third embodiments
disclosed herein, the at least one vinyl aromatic monomer comprises
styrene. Non-limiting examples of suitable conjugated
diene-containing polymers or copolymers for use in the rubber
compositions according to certain embodiments of the first-third
embodiments disclosed herein include, but are not limited to, at
least one of styrene-butadiene rubber (also referred to as SBR or
styrene-butadiene copolymer), polybutadiene, natural rubber,
ethylene propylene diene monomer rubber (also known as EPDM
rubber), butyl rubber, neoprene, or polyisoprene. In certain
embodiments of the first-third embodiments disclosed herein
styrene-butadiene copolymer can be understood to mean a copolymer
of styrene and butadiene monomers without any other monomers. In
certain embodiments of the first-third embodiments disclosed
herein, polybutadiene can be understood to mean a homopolymer of
butadiene monomers (e.g., 1,3-butadiene); in certain such
embodiments, the polybutadiene has a cis bond content of at least
80%, more preferably at least 90%, at least 92% or at least 95%. In
certain embodiments of the first-third embodiment disclosed herein,
polyisoprene can be understood to mean a homopolymer of isoprene
monomers.
In certain embodiments according to the first-third embodiments
disclosed herein, the at least one conjugated diene-containing
polymer or copolymer of the rubber composition, particularly
styrene-butadiene types or polybutadiene types, may comprise a
functionalized conjugated diene-containing polymer or copolymer. As
used herein, the term "functionalized conjugated diene-containing
polymer or copolymer" should be understood to include polymers and
copolymers with a functional group at one or both terminus (e.g.,
from use of a functionalized initiator, a functionalized
terminator, or both), a functional group along the main chain of
the polymer or copolymer, and combinations thereof. For example, a
silica-reactive functionalized elastomer may have the functional
group at one or both terminus, in the main chain thereof, or both.
In certain such embodiments, the rubber composition comprises about
5 to 100 phr of at least one functionalized conjugated
diene-containing polymer or copolymer, including 5 to 100 phr,
about 5 to about 90 phr, 5 to 90 phr, about 5 to about 70 phr, 5 to
70 phr, about 5 to about 50 phr, 5 to 50 phr, about 5 to about 40
phr, 5 to 40 phr, about 5 to about 30 phr, 5 to 30 phr, about 10 to
about 90 phr, 10 to 90 phr, about 10 to about 70 phr, 10 to 70 phr,
about 10 to about 50 phr, 10 to 50 phr, about 10 to about 40 phr,
10 to 40 phr, about 10 to about 30 phr, and 10 to 30 phr. In
certain embodiments according to the first-third embodiments
disclosed herein, the functionalized conjugated diene-containing
polymer or copolymer comprises a conjugated diene-containing
polymer or copolymer with a silica-reactive functional group.
Non-limiting examples of silica-reactive functional groups that are
known to be utilized in functionalizing conjugated diene-containing
polymers or copolymers and that are suitable for use in the rubber
compositions of certain embodiments of the first-third embodiments
include nitrogen-containing functional groups, silicon-containing
functional groups, oxygen- or sulfur-containing functional groups,
and metal-containing functional groups.
Non-limiting examples of nitrogen-containing functional groups that
are known to be utilized in functionalizing conjugated
diene-containing polymer or copolymers include, but are not limited
to, any of a substituted or unsubstituted amino group, an amide
residue, an isocyanate group, an imidazolyl group, an indolyl
group, a nitrile group, a pyridyl group, and a ketimine group. The
foregoing substituted or unsubstituted amino group should be
understood to include a primary alkylamine, a secondary alkylamine,
or a cyclic amine, and an amino group derived from a substituted or
unsubstituted imine. In certain embodiments according to the
first-third embodiments disclosed herein, the rubber composition
comprises a functionalized conjugated diene-containing polymer or
copolymer having at least one functional group selected from the
foregoing list of nitrogen-containing functional groups.
Non-limiting examples of silicon-containing functional groups that
are known to be utilized in functionalizing conjugated
diene-containing polymers or copolymers include, but are not
limited to, an organic silyl or siloxy group, and more precisely,
the functional group may be selected from an alkoxysilyl group, an
alkylhalosilyl group, a siloxy group, an alkylaminosilyl group, and
an alkoxyhalosilyl group. Suitable silicon-containing functional
groups for use in functionalizing conjugated diene-containing
polymers or copolymers also include those disclosed in U.S. Pat.
No. 6,369,167, the entire disclosure of which is herein
incorporated by reference. In certain embodiments according to the
first-third embodiments disclosed herein, the rubber composition
comprises a functionalized conjugated diene-containing polymer or
copolymer having at least one functional group selected from the
foregoing list of silicon-containing functional groups.
Non-limiting examples of oxygen- or sulfur-containing functional
groups that are known to be utilized in functionalizing conjugated
diene-containing polymers or copolymers include, but are not
limited to, a hydroxyl group, a carboxyl group, an epoxy group, a
glycidoxy group, a diglycidylamino group, a cyclic dithiane-derived
functional group, an ester group, an aldehyde group, an alkoxy
group, a ketone group, a thiocarboxyl group, a thioepoxy group, a
thioglycidoxy group, a thiodiglycidylamino group, a thioester
group, a thioaldehyde group, a thioalkoxy group, and a thioketone
group. In certain embodiments, the foregoing alkoxy group may be an
alcohol-derived alkoxy group derived from a benzophenone. In
certain embodiments according to the first-third embodiments
disclosed herein, the rubber composition comprises a functionalized
conjugated diene-containing polymer or copolymer having at least
one functional group selected from the foregoing list of oxygen- or
sulfur-containing functional groups.
Generally, conjugated diene-containing polymers and copolymers may
be prepared and recovered according to various suitable methods
such as batch, semi-continuous, or continuous operations, as are
well known to those having skill in the art. The polymerization can
also be carried out in a number of different polymerization reactor
systems, including but not limited to bulk polymerization, vapor
phase polymerization, solution polymerization, suspension
polymerization, coordination polymerization, and emulsion
polymerization. The polymerization may be carried out using a free
radical mechanism, an anionic mechanism, a cationic mechanism, or a
coordination mechanism. All of the above polymerization methods are
well known to persons skilled in the art.
Saturated Triglyceride Component
As discussed above, according to the first-third embodiments, a
saturated triglyceride component having a melting point of at least
40.degree. C. is included in the rubber composition. One or more
than one saturated triglyceride component can be utilized according
to embodiments of the first-third embodiment. The saturated
triglyceride component refers to an ingredient containing primarily
saturated fatty acid(s) (as opposed to mono- or polyunsaturated
fatty acids) in triglyceride form (i.e., three fatty acids bound to
a glycerol backbone as opposed to free fatty acids, monoglycerides
or diglycerides). In certain preferred embodiments of the
first-third embodiments disclosed herein, the saturated
triglyceride component contains (or comprises) at least 90%, at
least 92%, at least 95%, at least 98% or more saturated fatty
acid(s) in triglyceride form. In other words, in such embodiments,
the amount of saturated fatty acids appearing as free fatty acids,
monoglycerides, or diglycerides as well as the amount of
unsaturated (mono- and/or polyunsaturated) fatty acids appearing as
free fatty acids, monoglycerides, diglycerides or triglycerides is
limited to a total of less than 10% by weight, less than 8% by
weight, less than 5% by weight, less than 2% by weight, less than
1% by weight, or even 0% by weight (based upon the total weight of
the saturated triglyceride component). In certain preferred
embodiments of the first-third embodiments disclosed herein, the
amount of saturated fatty acids appearing as free fatty acids or a
salt thereof, monoglycerides, or diglycerides as well as the amount
of unsaturated (mono- and/or polyunsaturated) fatty acids appearing
as free fatty acids or a salt thereof, monoglycerides, diglycerides
or triglycerides is limited to a total of less than 10% by weight,
less than 8% by weight, less than 5% by weight, less than 2% by
weight, less than 1% by weight, or even 0% by weight (based upon
the total weight of the saturated triglyceride component).
According to the first-third embodiments, the saturated
triglyceride component (which, as discussed above, contains
saturated fatty acids bound to a glycerol backbone) can be
contrasted with ingredients such as stearic acid (which is a free
fatty acid known for use as a vulcanization activator). Likewise,
according to the first-third embodiments, the saturated
triglyceride component can be contrasted with soaps or salts of
fatty acids (e.g., zinc salts or "soaps" of free fatty acids which
are known for use as a processing aid).
In certain embodiments of the first-third embodiments, the rubber
composition includes (comprises) about 1 to about 60 phr or 1 to 60
phr (e.g., 5 phr, 10 phr, 15 phr, 20 phr, 25 phr, 30 phr, 35 phr,
40 phr, 45 phr, 50 phr, 55 phr or 60 phr) of the saturated
triglyceride component. In certain preferred embodiments of the
first-third embodiments, the rubber composition includes
(comprises) more than 5 phr of the saturated triglyceride
component. In certain such embodiments of the first-third
embodiments, the rubber composition includes (comprises) more than
5 phr and up to 60 phr, or more than 5 phr and up to 25 phr (e.g.,
more than 5 up to 25 phr) of the saturated triglyceride component.
In certain embodiments of the first-third embodiments, the rubber
composition includes more than 5 phr and up to 55 phr, more than 5
phr and up to 50 phr, more than 5 phr and up to 45 phr, more than 5
phr and up to 40 phr, more than 5 phr and up to 35 phr, or more
than 5 phr and up to 30 phr. By stating that more than 5 phr and up
to X phr of the saturated triglyceride component can be used it is
intended to encompass values of more than 5 phr (e.g., 6 phr, 7
phr, etc) as well as values larger than this and up to X phr (e.g.,
X-2 phr, X-1 phr, X phr, etc).
In certain embodiments of the first-third embodiments, the melting
point of the saturated triglyceride component is 40 to 100.degree.
C. (e.g., 40.degree. C., 45.degree. C., 50.degree. C., 55.degree.
C., 60.degree. C., 65.degree. C., 70.degree. C., 75.degree. C.,
80.degree. C., 85.degree. C., 90.degree. C., 95.degree. C., or
100.degree. C.). In certain embodiments of the first-third
embodiments, the melting point of the saturated triglyceride
component is at least 60.degree. C., 60 to 100.degree. C. (e.g.,
60.degree. C., 65.degree. C., 70.degree. C., 75.degree. C.,
80.degree. C., 85.degree. C., 90.degree. C., 95.degree. C., or
100.degree. C.), 60 to about 95.degree. C., 60 to 95.degree. C., 60
to 90.degree. C., 60 to 85.degree. C., 60 to 80.degree. C., or 60
to 75.degree. C. According to the first-third embodiments, when
more than one saturated triglyceride component is utilized, each
should have a melting point within one of the foregoing ranges.
According to the first-third embodiments disclosed herein, the
saturated triglyceride component may comprise one or more than one
type of saturated fatty acid triglyceride. In other words, the
three fatty acids bonded to a glycerol backbone within the
saturated triglyceride component may all be the same fatty acid or
may be different fatty acids, and the overall saturated fatty acid
component may comprise combination of one or more such saturated
triglycerides. In certain embodiments of the first-third
embodiments disclosed herein, at least 25% by weight of the
saturated fatty acids within the saturated triglyceride component
have a chain length of C18 or higher. In certain such embodiments,
at least 30%, at least 35%, at least 40%, at least 45%, at least
50%, at least 55%, at least 60%, at least 65%, at least 70%, at
least 75%, at least 80%, at least 85%, at least 90%, at least 95%,
or even 100% by weight of the saturated fatty acids within the
saturated triglyceride component have a chain length of C18 or
higher. In certain embodiments of the first-third embodiments
disclosed herein, at least 25% by weight of all fatty acids within
the saturated triglyceride component comprise saturated fatty acids
having a chain length of C18 or higher. In certain such
embodiments, at least 30%, at least 35%, at least 40%, at least
45%, at least 50%, at least 55%, at least 60%, at least 65%, at
least 70%, at least 75%, at least 80%, at least 85%, at least 90%,
at least 95%, or even 100% by weight of the fatty acids within the
saturated triglyceride component comprise saturated fatty acids
having a chain length of C18 or higher. Exemplary saturated fatty
acids having a chain length of C18 or higher include stearic acid
(C18:0) which is also known as octadecanoic acid; arachidic acid
(C20:0) which is also known as eicosanoic acid; heneicosylic acid
(C21:0) which is also known as heneicosanoic acid; behenic acid
(C22:0) which is also known as docosanoic acid; tricosylic acid
(C23:0) which is also known as tricosanoic acid; lignoceric acid
(C24:0) which is also known as tetracosanoic acid; pentacosylic
acid (C25:0) which is also known as pentacosanoic acid; cerotic
acid (C26:0) which is also known as hexacosanoic acid; heptacosylic
acid (C27:0) which is also known as heptacosanoic acid; montanic
acid (C28:0) which is also known as octacosanoic acid; nonacosylic
acid (C29:0) which is also known as nonacosanoic acid; melissic
acid (C30:0) which is also known as triacontanoic acid;
henatriacontylic acid (C31:0) which is also known as
henatriacontanoic acid; lacceroic acid (C32:0) which is also known
as dotriacontanoic acid; psyllic acid (C33:0) which is also known
as tritriacontanoic acid; geddic acid (C34:0) which is also known
as tetratriacontanoic acid; ceroplastic acid (C35:0) which is also
known as pentatriacontanoic acid; and hexatriacontylic acid (C36:0)
which is also known as hexatriacontanoic acid. According to certain
embodiments of the first-third embodiments disclosed herein, one or
more than one of the foregoing C18 or higher saturated fatty acids
may be present in one or the foregoing amounts.
In certain embodiments of the first-third embodiments disclosed
herein, the saturated triglyceride component comprises saturated
plant triglycerides. Various plant sources of saturated and
unsaturated plant triglycerides exist including grains, nuts and
vegetables. Common plant sources of saturated plant triglycerides
include, but are not limited to, soybean oil, palm oil, rapeseed
oil, sunflower seed, peanut oil, cottonseed oil, oil produced from
palm kernel, coconut oil, olive oil, corn oil, grape seed oil,
hazelnut oil, hemp oil, linseed oil, rice oil, safflower oil,
sesame oil, mustard oil, or flax oil. Generally, plant sources of
saturated plant triglycerides will contain only relatively minor
amounts of saturated plant triglycerides and major amounts of
unsaturated (mono- and/or polyunsaturated) triglycerides.
Therefore, in order to achieve a satisfactory level of saturated
plant triglycerides it may be necessary to concentrate or otherwise
process one or more plant sources of saturated triglycerides in
order to obtain a suitable saturated triglyceride component for use
in the first-third embodiments disclosed herein. The most common
saturated fatty acids occurring in plant triglycerides include
palmitic acid (C16:0) and stearic acid (C18:0). In certain
embodiments of the first-third embodiments at least 25%, at least
30%, at least 35%, at least 40%, at least 45%, at least 50%, at
least 55%, at least 60%, at least 65%, at least 70%, at least 75%,
at least 80%, at least 85%, at least 90%, at least 95%, or even
100% by weight of the saturated fatty acids within the saturated
triglyceride component comprise C18-C24 saturated fatty acids,
palmitic acid, stearic acid, or a combination of palmitic and
stearic acid. Alternatively, in certain embodiments of the
first-third embodiments at least at least 30%, at least 35%, at
least 40%, at least 45%, at least 50%, at least 55%, at least 60%,
at least 65%, at least 70%, at least 75%, at least 80%, at least
85%, at least 90%, at least 95%, or even 100% by weight of the
fatty acids within the saturated triglyceride component comprise
C18-C24 saturated fatty acids, palmitic acid, stearic acid, or a
combination of palmitic and stearic acid. One form of processing
that may be utilized to obtain a satisfactory level of saturated
plant triglycerides in certain embodiments of the first-third
embodiments is hydrogenation of unsaturated triglycerides.
In certain embodiments of the first-third embodiments, the
saturated triglyceride component comprises saturated animal
triglycerides. While sources of animal triglycerides will generally
contain higher percentages of saturated triglycerides than source
of plant triglycerides, it may still be necessary to concentrate or
otherwise process one or more animal sources of saturated
triglycerides in order to obtain a suitable saturated triglyceride
component for use in the first-third embodiments disclosed
herein.
In certain embodiments of the first-third embodiments, the
saturated triglyceride component comprises a combination of
saturated animal triglycerides and saturated plant triglycerides.
Alternatively, in certain embodiments of the first-third
embodiments disclosed herein, the saturated triglyceride component
may be synthetically produced or contain synthetically produced
saturated triglycerides. In yet other embodiments of the
first-third embodiments disclosed herein the saturated triglyceride
component comprises synthetically produced saturated triglycerides
in combination with: saturated animal triglycerides, saturated
plant triglycerides or both saturated animal and saturated plant
triglycerides.
Reinforcing Filler
As discussed above, according to the first-third embodiments, about
5 to about 200 phr of at least one reinforcing filler is included
in the rubber composition. In certain embodiments of the
first-third embodiments, the at least one reinforcing filler
comprises carbon black, silica, or a combination thereof. By
stating that at least one reinforcing filler is utilized is meant
that one filler or more than one filler (e.g., two fillers, three
fillers, or more) can be utilized. By stating that the at least one
reinforcing filler comprises carbon black, silica, or a combination
thereof is meant that one or more than one filler can be utilized
and that when more than one filler is utilized it can be any
combination of carbon black and silica (e.g., one carbon black and
one silica, two carbon blacks, two silicas, one carbon black and
two silicas, two carbon blacks and two silicas, etc.).
As used herein, the term "reinforcing" as used with respect to the
phrases such as "reinforcing filler," "reinforcing carbon black
filler," and "reinforcing silica filler" generally should be
understood to encompass both fillers that are traditionally
described as reinforcing as well as fillers that may be described
as semi-reinforcing. Traditionally, the term "reinforcing filler"
is used to refer to a particulate material that has a nitrogen
absorption specific surface area (N.sub.2SA) of more than about 100
m.sup.2/g, and in certain instances more than 100 m.sup.2/g, more
than about 125 m.sup.2/g, more than 125 m.sup.2/g, or even more
than about 150 m.sup.2/g or more than 150 m.sup.2/g. Alternatively
or additionally, the traditional use of the term "reinforcing
filler" can also be used to refer to a particulate material that
has a particle size of about 10 nm to about 50 nm (including 10 nm
to 50 nm). Traditionally, the term "semi-reinforcing filler" is
used to refer to a filler that is intermediary in either particle
size, surface area (N.sub.2SA), or both, to a non-reinforcing
filler and a reinforcing filler. In certain embodiments of the
first-third embodiments disclosed herein, the term "reinforcing
filler" is used to refer to a particulate material that has a
nitrogen absorption specific surface area (N.sub.2SA) of about 20
m.sup.2/g or greater, including 20 m.sup.2/g or greater, more than
about 50 m.sup.2/g, more than 50 m.sup.2/g, more than about 100
m.sup.2/g, more than 100 m.sup.2/g, more than about 125 m.sup.2/g,
and more than 125 m.sup.2/g. In certain embodiments of the
first-third embodiments disclosed herein, the term "reinforcing
filler" is additionally or alternatively used to refer to a
particulate material that has a particle size of about 10 nm up to
about 1000 nm, including 10 nm up to 1000 nm, about 10 nm up to
about 50 nm, and 10 nm up to 50 nm. Surface area values for carbon
black fillers as used in this application can be determined by ASTM
Standard Test Method D6556 (as of the time of filing this
application most recently issued as D6556-14 in 2014) using a
B.E.T. nitrogen absorption method. Surface area values for silica
fillers as used in this application can be determined by ASTM
Standard Test Method D1993 (as of the time of filing this
application most recently issued as D1993-03 (reapproved in 2013))
using a multipoint B.E.T. nitrogen absorption method.
As used herein, the term "non-reinforcing filler" refers to a
particulate material that has a nitrogen surface area of less than
about 20 m.sup.2/g (including less than 20 m.sup.2/g), and in
certain embodiments less than about 10 m.sup.2/g (including less
than 10 m.sup.2/g). The nitrogen surface area of such a
non-reinforcing filler particulate material can be determined
according to various standard methods (including ASTM D6556 or
D3037). In certain embodiments of the first-third embodiments
disclosed herein, the term "non-reinforcing filler" is additionally
or alternatively used to refer to a particulate material that has a
particle size of greater than about 1000 nm (including greater than
1000 nm).
The total amount of reinforcing filler used in the rubber
compositions of the first-third embodiments may vary between about
5 and about 200 phr, including 5 to 200 phr (e.g., 5 phr, 10 phr,
15 phr, 20 phr, 25 phr, 30 phr, 35 phr, 40 phr, 45 phr, 50 phr, 60
phr, 70 phr, 80 phr, 90 phr, 100 phr, 110 phr, 120 phr, 130 phr,
140 phr, 150 phr, 160 phr, 170 phr, 180 phr, 190 phr, or 200 phr),
about 5 to about 150 phr, 5 to 150 phr, about 5 to about 100 phr, 5
to 100 phr, about 10 to about 150 phr, 10 to 150 phr, about 10 to
about 100 phr, 10 to 100 phr, about 20 to about 150 phr, 20 to 150
phr, about 20 to about 100 phr, 20 to 100 phr, about 30 to about
150 phr, 30 to 150 phr, about 30 to about 100 phr, or 30 to 100
phr.
Various carbon blacks in varying amounts are suitable for use in
those embodiments of the first-third embodiments which utilize one
or more carbon blacks as a filler. In certain embodiments of the
first-third embodiments disclosed herein, the rubber composition
comprises about 5 to about 100 phr (including 5 to 100 phr) of one
or more carbon blacks. In certain embodiments of the first-third
embodiments disclosed herein, the total amount of carbon black
filler is 5 to 100 phr, including about 10 to about 100 phr, 10 to
100 phr, about 10 to about 90 phr, 10 to 90 phr, about 25 to about
90 phr, 25 to 90 phr, about 35 to about 90 phr, 35 to 90 phr, about
25 to about 80 phr, 25 to 80 phr, about 35 to about 80 phr, or 35
to 80 phr. Generally, suitable carbon black for use in the rubber
composition of certain embodiments of the first-third embodiments
disclosed herein includes any of the commonly available,
commercially-produced carbon blacks, including those having a
surface area of at least about 20 m.sup.2/g (including at least 20
m.sup.2/g) and, more preferably, at least about 35 m.sup.2/g up to
about 200 m.sup.2/g or higher (including 35 m.sup.2/g up to 200
m.sup.2/g). Among the useful carbon blacks are furnace black,
channel blacks, and lamp blacks. More specifically, examples of
useful carbon blacks include super abrasion furnace (SAF) blacks,
high abrasion furnace (HAF) blacks, fast extrusion furnace (FEF)
blacks, fine furnace (FF) blacks, intermediate super abrasion
furnace (ISAF) blacks, semi-reinforcing furnace (SRF) blacks,
medium processing channel blacks, hard processing channel blacks
and conducting channel blacks. Other carbon blacks which can be
utilized include acetylene blacks. In certain embodiments of the
first-third embodiments disclosed herein, the rubber composition
includes a mixture of two or more of the foregoing blacks. Typical
suitable carbon blacks for use in certain embodiments of the
first-third embodiments disclosed herein are N-110, N-220, N-339,
N-330, N-351, N-550, and N-660, as designated by ASTM D-1765-82a.
The carbon blacks utilized can be in pelletized form or an
unpelletized flocculent mass. Preferably, for more uniform mixing,
unpelletized carbon black is preferred. As those of skill in the
art will understand, most carbon blacks are reinforcing fillers.
However, non-reinforcing carbon black fillers can alternatively (in
one of the foregoing amounts) or additionally (e.g., in combination
with one or more reinforcing carbon blacks in a total amount
equating to one of the foregoing amounts) be utilized. Non-limiting
examples of non-reinforcing carbon blacks include, but are not
limited to, thermal blacks or the N9 series carbon blacks (also
referred to as the N-900 series), such as those with the ASTM
designation N-907, N-908, N-990, and N-991. Various carbon blacks
meeting the foregoing are commercially available, including but not
limited to Thermax.RTM. N990 carbon black from Cancarb Limited
(Medicine Hat, Alberta, Canada).
Various silica fillers in varying amounts are suitable for use in
those embodiments of the first-third embodiments which utilize one
or more silicas as a filler. The amount of silica filler(s)
utilized can vary and in certain embodiments of the first-third
embodiments disclosed herein, the rubber composition comprises
about 5 to about 200 phr of silica filler. One or more than one
silica filler may be utilized in the rubber compositions according
to the first-third embodiments disclosed herein. In certain
embodiments of the first-third embodiments disclosed herein, the
total amount of silica filler is 5 to 200 phr, including about 10
to about 200 phr, 10 to 200 phr, about 10 to about 175 phr, 10 to
175 phr, about 25 to about 150 phr, 25 to 150 phr, about 35 to
about 150 phr, 35 to 150 phr, about 25 to about 125 phr, 25 to 125
phr, about 25 to about 100 phr, 25 to 100 phr, about 25 to about 80
phr, 25 to 80 phr, about 35 to about 125 phr, 35 to 125 phr, about
35 to about 100 phr, 35 to 100 phr, about 35 to about 80 phr, and
35 to 80 phr of at least one filler. In certain embodiments, the
useful upper range for the amount of silica filler can be
considered to be somewhat limited by the high viscosity imparted by
fillers of this type.
Non-limiting examples of silica fillers suitable for use in the
rubber compositions of certain embodiments of the first-third
embodiments disclosed herein include, but are not limited to,
precipitated amorphous silica, wet silica (hydrated silicic acid),
dry silica (anhydrous silicic acid), fumed silica, calcium silicate
and the like. Other suitable reinforcing silica fillers for use in
rubber compositions of certain embodiments of the first-third
embodiments disclosed herein include, but are not limited to,
aluminum silicate, magnesium silicate (Mg.sub.2SiO.sub.4,
MgSiO.sub.3 etc.), magnesium calcium silicate (CaMgSiO.sub.4),
calcium silicate (Ca.sub.2SiO.sub.4 etc.), aluminum silicate
(Al.sub.2SiO.sub.5, Al.sub.4.3SiO.sub.4.5H.sub.2O etc.), aluminum
calcium silicate (Al.sub.2O.sub.3.CaO.sub.2SiO.sub.2, etc.), and
the like. Among the listed reinforcing silica fillers, precipitated
amorphous wet-process, hydrated silica fillers are preferred. Such
reinforcing silica fillers are produced by a chemical reaction in
water, from which they are precipitated as ultrafine, spherical
particles, with primary particles strongly associated into
aggregates, which in turn combine less strongly into agglomerates.
The surface area, as measured by the BET method, is a preferred
measurement for characterizing the reinforcing character of
different reinforcing silica fillers. In certain embodiments of the
first-third embodiments disclosed herein, the rubber composition
comprises a reinforcing silica filler having a surface area (as
measured by the BET method) of about 32 m.sup.2/g to about 400
m.sup.2/g (including 32 m.sup.2/g to 400 m.sup.2/g), with the range
of about 100 m.sup.2/g to about 300 m.sup.2/g (including 100
m.sup.2/g to 300 m.sup.2/g) being preferred, and the range of about
150 m.sup.2/g to about 220 m.sup.2/g (including 150 m.sup.2/g to
220 m.sup.2/g) being included. In certain embodiments of the
first-third embodiments disclosed herein, the rubber composition
comprises reinforcing silica filler having a pH of about 5.5 to
about 7 or slightly over 7, preferably about 5.5 to about 6.8. Some
of the commercially available reinforcing silica fillers which can
be used in the rubber compositions of certain embodiments of the
first-third embodiments disclosed herein include, but are not
limited to, Hi-Sil.RTM. 190, Hi-Sil.RTM. 210, Hi-Sil.RTM. 215,
Hi-Sil.RTM. 233, Hi-Sil.RTM. 243, and the like, produced by PPG
Industries (Pittsburgh, Pa.). As well, a number of useful
commercial grades of different reinforcing silica fillers are also
available from Degussa Corporation (e.g., VN2, VN3), Rhone Poulenc
(e.g., Zeosil.TM. 1165 MP), and J. M. Huber Corporation.
In certain embodiments of the first-third embodiments disclosed
herein, as discussed in more detail below, a reinforcing silica
filler comprising a silica that has been pre-treated with a silica
coupling agent may be utilized; preferably any pre-treated silica
comprises a silica that has been pre-treacted with a
silane-containing silica coupling agent.
In certain embodiments of the first-third embodiments, at least one
additional filler (e.g., in addition to the above-discussed carbon
black and/or silica fillers) is present in the rubber composition.
The particular amount and type of any such additional filler may
vary. Non-limiting examples of suitable additional fillers for use
in certain embodiments of the first-third embodiments include, but
are not limited to talc, clay, alumina (Al.sub.2O.sub.3), aluminum
hydrate (Al.sub.2O.sub.3H.sub.2O), aluminum hydroxide
(Al(OH).sub.3), aluminum carbonate (Al.sub.2(CO.sub.3).sub.2),
aluminum nitride, aluminum magnesium oxide (MgOAl.sub.2O.sub.3),
pyrofilite (Al.sub.2O.sub.34SiO.sub.2.H.sub.2O), bentonite
(Al.sub.2O.sub.3.4SiO.sub.2.2H.sub.2O), boron nitride, mica,
kaolin, glass balloon, glass beads, calcium oxide (CaO), calcium
hydroxide (Ca(OH).sub.2), calcium carbonate (CaCO.sub.3), magnesium
hydroxide (MH(OH).sub.2), magnesium oxide (MgO), magnesium
carbonate (MgCO.sub.3), titanium oxide, titanium dioxide, potassium
titanate, barium sulfate, zirconium oxide (ZrO.sub.2), zirconium
hydroxide [Zr(OH).sub.2.nH.sub.2O], zirconium carbonate
[Zr(CO.sub.3).sub.2], crystalline aluminosilicates, reinforcing
grades of zinc oxide (i.e., reinforcing zinc oxide), and
combinations thereof. The total amount of any such additional
filler present in the rubber compositions of the first-third
embodiments may vary from about 1 to about 100 phr, including 1 to
100 phr, at least 1 phr, at least 5 phr, at least 10 phr, less than
100 phr, less than 90 phr, less than 80 phr, less than 70 phr, less
than 60 phr, less than 50 phr, or amounts within the foregoing.
Other Ingredients
In those embodiments of the first-third embodiments disclosed
herein where the rubber composition includes silica filler, the
composition will also preferably include (further comprise) one or
more silica coupling agents. Silica coupling agents are useful in
preventing or reducing aggregation of the silica filler within the
rubber composition. Aggregates of the silica filler particles are
believed to undesirably increase the viscosity of the rubber
composition, and, therefore, preventing this aggregation reduces
the viscosity and improves the processibility and blending of the
rubber composition.
Generally, any conventional type of silica coupling agent can be
used in those embodiments of the first-third embodiments which
include one or more silica coupling agents, such as those having a
silane and a constituent component or moiety that can react with a
polymer, particularly a vulcanizable polymer. The silica coupling
agent acts as a connecting bridge between silica and the polymer.
Suitable silica coupling agents include those containing groups
such as alkyl alkoxy, mercapto, blocked mercapto,
sulfide-containing (e.g., monosulfide-based alkoxy-containing,
disulfide-based alkoxy-containing, tetrasulfide-based
alkoxy-containing), amino, vinyl, epoxy, and combinations thereof.
In certain embodiments of the first-third embodiments, the silica
coupling agent is in the form of a pre-treated silica, i.e., a
pre-treacted silica has been pre-surface treated with a silane
prior to being added to the rubber composition. The use of a
pre-treated silica can allow for two ingredients (i.e., silica and
a silica coupling agent) to be added in one ingredient, which
generally tends to make rubber compounding easier.
The amount of silica coupling agent used in those embodiments of
the first-third embodiments which include a silica coupling agent
may vary. In certain embodiments of the first-third embodiments
disclosed herein, the silica coupling agent is present in an amount
sufficient to provide a ratio of the total amount of silica
coupling agent to reinforcing silica filler of 1:100 to 1:5 (i.e.,
1 to 20 parts by weight per 100 parts of silica), including 1:100
to 1:10, 1:100 to 1:20, 1:100 to 1:25 as well as 1:100 to 1:50. In
certain embodiments according to the first-third embodiments
disclosed herein, the amount of silica coupling agent in the rubber
composition is 0.01 to 10 phr, 0.01 to 5 phr, or 0.01 to 3 phr.
In certain embodiments of the first-third embodiments disclosed
herein, the rubber composition may comprise one or more additional
ingredients such as oils (processing and extender), waxes,
processing aids, tackifying resins, reinforcing resins,
antioxidants, peptizers, or a cure package (i.e., at least one of a
vulcanizing agent, a vulcanizing accelerator, a vulcanizing
additive, a vulcanizing inhibitor, or an anti-scorching agent). In
certain embodiments of the first-third embodiments, one or more
than one of each of the foregoing types of ingredients may be
present in the rubber composition.
Various types of tackifying resins are known to those of skill in
the art and may be utilized in the rubber compositions of certain
embodiments of the first-third embodiments; these include but not
limited to: rosin and its derivatives, hydrocarbon resins, and
phenol-formaldehyde resins. One or more than one type as well as
one or more than one of each type may be utilized in certain
embodiments of the first-third embodiments. As used herein the term
"resin" is intended to encompass compounds which are solid (or
semi-solid) at room temperature (23.degree. C.) as opposed to being
liquid (such as oils) at room temperature. Exemplary types of
rosin-type resins include, but are not limited to, gum rosin, wood
rosin, tall oil rosin, rosin esters, and combinations thereof.
Exemplary types of hydrocarbon resins include, but are not limited
to, cyclopentadiene or dicyclopentadiene homopolymer or copolymer
resins; terpene/phenol homopolymer or copolymer resins; C5 or C9
fraction homopolymer or copolymer resins; alpha-methylstyrene
homopolymer or copolymer resins, and combinations thereof.
Exemplary types of phenol-formaldehyde resins include, but are not
limited to, those containing alkyl phenols. In certain embodiments
of the first-third embodiments, the total amount of tackifying
resin used is 1 to 25 phr, including 1 to 20 phr, 1 to 15 phr and 1
to 10 phr. In certain embodiments of the first-third embodiments,
the total amount of phenolic resin, acrylic resin, and
polyphenylene resin is no more than 25 phr, including no more than
20 phr, no more than 15 phr, no more than 10 phr, and no more than
5 phr.
Various antioxidants are known to those of skill in the art and may
be utilized in the rubber compositions of certain embodiments of
the first-third embodiments; these include but are not limited to
phenolic antioxidants, amine phenol antioxidants, hydroquinone
antioxidants, alkyldiamine antioxidants, and amine compound
antioxidants such as N-phenyl-N'-isopropyl-p-phenylenediamine
(IPPD), or N-(1,3-dimethylbutyl)-N'-phenyl-phenylenediamine (6PPD).
One or more than one type as well as one or more than one of each
type may be utilized in certain embodiments of the first-third
embodiments. In certain embodiments of the first-third embodiments,
the total amount of antioxidant(s) used is 1 to 5 phr.
In certain embodiments of the first-third embodiments, various
types of processing and extender oils may be utilized, including,
but not limited to aromatic, naphthenic, and low PCA oils. Suitable
low PCA oils include those having a polycyclic aromatic content of
less than 3 percent by weight as determined by the IP346 method.
Procedures for the IP346 method may be found in Standard Methods
for Analysis & Testing of Petroleum and Related Products and
British Standard 2000 Parts, 2003, 62nd edition, published by the
Institute of Petroleum, United Kingdom. Suitable low PCA oils
include mild extraction solvates (MES), treated distillate aromatic
extracts (TDAE), TRAE, and heavy naphthenics. Suitable MES oils are
available commercially as CATENEX SNR from SHELL, PROREX 15, and
FLEXON 683 from EXXONMOBIL, VIVATEC 200 from BP, PLAXOLENE MS from
TOTAL FINA ELF, TUDALEN 4160/4225 from DAHLEKE, MES-H from REPSOL,
MES from Z8, and OLIO MES 5201 from AGIP. Suitable TDAE oils are
available as TYREX 20 from EXXONMOBIL, VIVATEC 500, VIVATEC 180,
and ENERTHENE 1849 from BP, and EXTENSOIL 1996 from REPSOL.
Suitable heavy naphthenic oils are available as SHELLFLEX 794,
ERGON BLACK OIL, ERGON H2000, CROSS C2000, CROSS C2400, and SAN
JOAQUIN 2000L. Suitable low PCA oils also include various
plant-sourced oils such as can be harvested from vegetables, nuts,
and seeds. Non-limiting examples include, but are not limited to,
soy or soybean oil, sunflower oil (including high oleic sunflower
oil), safflower oil, corn oil, linseed oil, cotton seed oil,
rapeseed oil, cashew oil, sesame oil, camellia oil, jojoba oil,
macadamia nut oil, coconut oil, and palm oil. The foregoing
processing oils can also be used as an extender oil, i.e., to
prepare an oil-extended polymer or copolymer or as a processing or
free oil. Generally, for most uses of the rubber compositions in
tire components the total amount of oil used (processing oil and
extender oil) in the rubber compositions and methods disclosed
herein ranges about 1 to about 40 phr, 1 to 40 phr, about 1 to
about 20 phr, or 1 to 20 phr. In certain embodiments of the
first-third embodiments disclosed herein, the use of the saturated
triglyceride component allows for a reduction in the amount of or
even elimination of oil (processing and/or extender oil) that would
otherwise be utilized in the rubber composition. Accordingly, in
certain embodiments of the first-third embodiments disclosed
herein, the rubber composition comprises (contains) no more than 10
phr (in total) of petroleum oil, mineral oil, or plant oil; in
certain such embodiments, the total amount of petroleum oil,
mineral oil, and plant oil in the rubber composition is less than
10 phr, less than 8 phr, less than 5 phr, less than 3 phr, less
than 2 phr, less than 1 phr, or even 0 phr. As used herein the term
plant oil is used to refer to plant triglycerides which have a
melting point of less than 40.degree. C., and frequently less than
30.degree. C., or less than 25.degree. C.
In certain embodiments of the first-third embodiments disclosed
herein, the rubber composition includes at least one additional
polymer or copolymer (i.e., in addition to the at least one
conjugated diene-containing polymer or copolymer) in a minor
amount, e.g., 20 phr or less, 10 phr or less, or 5 phr or less.
Suitable such additional polymer or copolymers include one or more
of the following: styrene-isoprene rubber,
butadiene-isoprene-rubber, styrene-isoprene-butadiene rubber,
(polychloroprene), ethylene-propylene rubber,
acrylonitrile-butadiene rubber (NBR), silicone rubber, fluorinated
rubber, polyacrylate rubber (copolymer of acrylate monomer and
vinyl ether), ethylene acrylic rubber, ethylene vinyl acetate
copolymer (EVA), epichlorohydrin rubbers, chlorinated polyethylene
rubbers, chlorosulfonated polyethylene rubbers, nitrile rubber,
halogenated nitrile rubber, hydrogenated nitrile rubber, or
tetrafluoroethylene-propylene rubber. Examples of fluorinated
rubber include perfluoroelastomer rubber, fluoroelastomer,
fluorosilicone, and tetrafluoroethylene-propylene rubber.
In certain embodiments of the first-third embodiments, the rubber
composition includes (further comprises) a cure package. Generally,
the cure package includes at least one of: a vulcanizing agent; a
vulcanizing accelerator; a vulcanizing activator (e.g., zinc oxide,
stearic acid, and the like); a vulcanizing inhibitor, and an
anti-scorching agent. In certain embodiments of the first-third
embodiments, the cure package includes at least one vulcanizing
agent, at least one vulcanizing accelerator, at least one
vulcanizing activator and optionally a vulcanizing inhibitor and/or
an anti-scorching agent. Vulcanizing accelerators and vulcanizing
activators act as catalysts for the vulcanization agent.
Vulcanizing inhibitors and anti-scorching agents are known in the
art and can be selected by one skilled in the art based on the
vulcanizate properties desired.
Examples of suitable types of vulcanizing agents for use in certain
embodiments of the compositions and methods of the first-third
embodiments, include but are not limited to, sulfur or
peroxide-based curing components. Thus, in certain such
embodiments, the cure package includes a sulfur-based curative or a
peroxide-based curative. Examples of specific suitable sulfur
vulcanizing agents include "rubbermaker's" soluble sulfur; sulfur
donating curing agents, such as an amine disulfide, polymeric
polysulfide, or sulfur olefin adducts; and insoluble polymeric
sulfur. In certain embodiments of the first-third embodiments, the
sulfur vulcanizing agent is soluble sulfur or a mixture of soluble
and insoluble polymeric sulfur. For a general disclosure of
suitable vulcanizing agents and other components used in curing,
e.g., vulcanizing inhibitor and anti-scorching agents, one can
refer to Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed.,
Wiley Interscience, N.Y. 1982, Vol. 20, pp. 365 to 468,
particularly Vulcanization Agents and Auxiliary Materials, pp. 390
to 402, or Vulcanization by A. Y. Coran, Encyclopedia of Polymer
Science and Engineering, Second Edition (1989 John Wiley &
Sons, Inc.), both of which are incorporated herein by reference.
Vulcanizing agents can be used alone or in combination. Generally,
the vulcanizing agents are used in an amount ranging from 0.1 to 10
phr, including from 1 to 7.5 phr, including from 1 to 5 phr, and
preferably from 1 to 3.5 phr.
Vulcanizing accelerators are used to control the time and/or
temperature required for vulcanization and to improve properties of
the vulcanizate. Examples of suitable vulcanizing accelerators for
use in certain embodiments of the compositions and methods of the
first-third embodiments disclosed herein include, but are not
limited to, thiazole vulcanization accelerators, such as
2-mercaptobenzothiazole, 2,2'-dithiobis(benzothiazole) (MBTS),
N-cyclohexyl-2-benzothiazole-sulfenamide (CBS),
N-tert-butyl-2-benzothiazole-sulfenamide (TBBS), and the like;
guanidine vulcanization accelerators, such as diphenyl guanidine
(DPG) and the like; thiuram vulcanizing accelerators; carbamate
vulcanizing accelerators; and the like. Generally, the amount of
the vulcanization accelerator used ranges from 0.1 to 10 phr,
preferably 0.5 to 5 phr.
Vulcanizing activators are additives used to support vulcanization.
Generally vulcanizing activators include both an inorganic and
organic component. Zinc oxide is the most widely used inorganic
vulcanization activator. Various organic vulcanization activators
are commonly used including stearic acid, palmitic acid, lauric
acid, and zinc salts of each of the foregoing. Generally, the
amount of vulcanization activator used ranges from 0.1 to 6 phr,
preferably 0.5 to 4 phr.
Vulcanization inhibitors are used to control the vulcanization
process and generally retard or inhibit vulcanization until the
desired time and/or temperature is reached. Common vulcanization
inhibitors include, but are not limited to, PVI
(cyclohexylthiophthalmide) from Santogard. Generally, the amount of
vulcanization inhibitor is 0.1 to 3 phr, preferably 0.5 to 2
phr.
Processes for Preparing Rubber Compositions
The process used to prepare rubber compositions according to the
first-third embodiments is not particularly limited. In certain
embodiments of the first-third embodiments, the process comprises:
preparing a masterbatch from ingredients including the at least one
conjugated diene-containing polymer or copolymer, the saturated
triglyceride component, the at least one reinforcing filler and any
of the optional ingredients discussed above (generally with the
exception of any vulcanization agent and vulcanization accelerator)
and then preparing a final batch comprising the masterbatch along
with any vulcanization agent and vulcanization accelerator(s),
thereby resulting in a final rubber composition.
In certain embodiments of the first-third embodiments, the process
used to prepare the masterbatch may include more than one
masterbatch stage, e.g., an initial masterbatch followed by a
secondary masterbatch. In certain such embodiments, a portion of
silica filler is added in an initial masterbatch stage (optionally
along with a portion of the silane coupling agent) and the
remainder of the silica filler in a secondary masterbatch stage
(optionally along with a portion of the silane coupling agent). In
certain embodiments of the first-third embodiments, the process for
preparing the rubber composition further comprises a remill mixing
step subsequent to any masterbatch step but prior to preparing the
final batch; such a remill mixing step can be helpful in
incorporating the silica fillers into the rubber composition.
The preparation of the masterbatch(es) and the final batch may
generally involve mixing together the ingredients for the rubber
composition (as disclosed above) by methods known in the art, such
as, for example, by kneading the ingredients together in a Banbury
mixer or on a milled roll. The term masterbatch as used herein is
intended to refer to a non-productive mixing stage, which is known
to those of skill in the art and generally understood to be a
mixing stage where no vulcanizing agents or vulcanization
accelerators are added. The term final batch as used herein is
intended to refer to a productive mixing stage, which is also known
to those of skill in the art and generally understood to be the
mixing stage where the vulcanizing agents and vulcanization
accelerators are added into the rubber composition.
In certain embodiments of the first-third embodiments, the process
includes one or more master batch mixing stages conducted at a
temperature of about 130.degree. C. to about 200.degree. C., and
the final mixing stage is conducted at a temperature below the
vulcanization temperature in order to avoid unwanted pre-cure of
the rubber composition. Generally, the temperature of the
productive (or final) mixing stage should not exceed about
120.degree. C. and is typically about 40.degree. C. to about
120.degree. C., or about 60.degree. C. to about 110.degree. C. and,
especially, about 75.degree. C. to about 100.degree. C.
Tires and Tire Components
As discussed above, the second embodiment disclosed herein is
directed to a tire comprising at least one component made from a
rubber composition according to the first embodiment. In other
words, the tire comprises at least one component made from a rubber
composition comprising at least one conjugated diene-containing
polymer or copolymer, about 1 to about 60 phr of a saturated
triglyceride component having a melting point of at least
40.degree. C., and about 5 to about 200 phr of at least one
reinforcing filler. Moreover, the second embodiment should be
understood to include all of the variations in the rubber
composition according to the first embodiment as discussed above,
as if fully set forth in this section. According to the second
embodiment, the particular tire component made from a rubber
composition according to the first embodiment may vary. In certain
embodiments of the second embodiment, the at least one tire
component is a tread, subtread, sidewall, bead filler, or body ply
skim. In certain preferred embodiments of the second embodiment,
the at least one tire component comprises a tread, a bead filler,
or both. In certain preferred embodiments of the second embodiment,
the at least one tire component is a tread. In certain embodiments
of the second embodiment, the tire tread is incorporated into a
high-performance tire which can be understood as a tire having a
"V" or "Z" speed rating (with a "V" speed rating being up to 240
km/hour or up to 149 miles/hour and a "Z" speed rating being over
240 km/hour or over 149 miles/hour).
Methods for Improving Tire Performance
As discussed above, the third embodiment disclosed herein is
directed to a method for improving the performance (e.g., the wet
traction as measured by tan .delta. at 0.degree. C.) of a tire
tread. The method comprises incorporating about 1 to about 60 phr
of a saturated triglyceride component having a melting point of at
least 40.degree. C. into a rubber composition comprising at least
one conjugated diene-containing polymer or copolymer and 5 to 200
phr of at least one reinforcing filler. The method of the third
embodiment can also be understood as the use of a rubber
composition according to the first embodiment in the tread of a
tire which results in an improvement in the performance (e.g., the
wet traction as measured by tan .delta. at 0.degree. C.) of the
tire tread. Moreover, the methods of the third embodiment should be
understood to include all of the variations in the rubber
composition of the first embodiment as discussed above, as if fully
set forth in this section. According to the third embodiment, the
improvement in performance is as compared to a tire tread having a
rubber composition with the same ingredients other than having the
saturated triglyceride component replaced with an equivalent amount
of petroleum oil, preferably a low PCA petroleum oil or a
naphthenic oil. As those of skill in the art will understand, the
wet traction performance of a rubber composition when incorporated
into (used as) a tire tread can be predicted by measuring the tan
.delta. at 0.degree. C. of the rubber composition. Various methods
can be utilized for measuring tan .delta. at 0.degree. C. and the
values provided herein are measured according to the procedure
described in the Examples. The particular amount of improvement in
wet traction (as measured by tan .delta. at 0.degree. C.) achieved
by the method of the third embodiment may vary. An improvement in
wet traction will be evidenced by an increase in the value of tan
.delta. at 0.degree. C. In certain embodiments of the third
embodiment, the improvement in wet traction (as measured by tan
.delta. at 0.degree. C.) is at least 3%, at least 4%, at least
about 5%, at least 5%, at least 6%, at least 7%, at least 8%, at
least 9%, at least about 10%, at least 10%, at least 15%, at least
20%, at least 25%, or more. In certain embodiments of the third
embodiment, the improvement in wet traction (as measured by tan
.delta. at 0.degree. C.) is at least 3% to about 10%, at least 3%
to 15%, at least 3% to 20%, or at least 3% to 25%.
In certain embodiments of the third embodiment, at least one
additional aspect of performance of the tire tread is improved such
as dry traction (as measured by tan .delta. at 30.degree. C.),
handling (as measured by E' at 30.degree. C.), or rolling
resistance (as measured by tan .delta. at 60.degree. C.). According
to the third embodiment, the foregoing aspects of improved
performance are as compared to a tire tread having a rubber
composition with the same ingredients other than having the
saturated triglyceride component replaced with an equivalent amount
of petroleum oil, preferably a low PCA petroleum oil or a napthenic
oil. As those of skill in the art will understand, the dry traction
performance of a rubber composition when incorporated into (used
as) a tire tread can be predicted by measuring the tan .delta. at
30.degree. C. of the rubber composition, the handling can be
predicted by measuring E' at 30.degree. C., and the rolling
resistance can be predicted by measuring tan .delta. at 30.degree.
C. Various methods can be utilized for measuring each of these
properties, and the values provided herein are measured according
to the procedures described in the Examples.
In those embodiments of the third embodiment wherein an improvement
in dry traction (as measured by tan .delta. at 30.degree. C.) is
achieved, the particular amount of improvement may vary. An
improvement in dry traction will be evidenced by an increase in the
value of tan .delta. at 30.degree. C. In certain such embodiments
of the third embodiment, the improvement in dry traction (as
measured by tan .delta. at 30.degree. C.) is at least 3%, at least
4%, at least about 5%, at least 5%, at least 6%, at least 7%, at
least 8%, at least 9%, at least about 10%, at least 10%, at least
15%, at least 20%, at least 25%, or more. In certain embodiments of
the third embodiment, the improvement in dry traction (as measured
by tan .delta. at 30.degree. C.) is at least 3% to about 10%, at
least 3% to 15%, at least 3% to 20%, or at least 3% to 25%.
In those embodiments of the third embodiment wherein an improvement
in handling (as measured by E' at 30.degree. C.) is achieved, the
particular amount of improvement may vary. An improvement in
handling will be evidenced by an increase in the value of E' at
30.degree. C. In certain such embodiments of the third embodiment,
the improvement in handling (as measured by E' at 30.degree. C.) is
at least 5% (e.g., 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%,
55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% or 100% or more), at
least 10%, at least about 15%, at least 20%, at least 30%, at least
40%, at least 50%, at least 60%, at least about 70%, at least 80%,
at least 90%, or more. In certain embodiments of the third
embodiment, the improvement in dry traction (as measured by E' at
30.degree. C.) is at least 5% to 100%, at least 10% to 100%, at
least 15% to 100%, at least 5% to about 90%, at least 10% to about
90%, or at least 15% to about 90%. In certain embodiments of the
third embodiment wherein an improvement in handling (as measured by
E' at 30.degree. C.) is desired, the saturated triglyceride
component is limited to one having a melting point of at least
60.degree. C., 60.degree. C. to about 95.degree. C., 60 to
95.degree. C., 60 to about 98.degree. C., or 60 to 98.degree.
C.
In those embodiments of the third embodiment wherein an improvement
in rolling resistance (as measured by tan .delta. at 60.degree. C.)
is achieved, the particular amount of improvement may vary. An
improvement in rolling resistance will be evidenced by a decrease
in the value of tan .delta. at 60.degree. C. When an improvement in
rolling resistance is desired, the saturated triglyceride component
may be limited to one having a melting point of 40.degree. C. to
about 55.degree. C., 40 to 55.degree. C., or 40 to less than
60.degree. C. In certain embodiments of the third embodiment, the
improvement in rolling resistance (as measured by tan .delta. at
60.degree. C.) is at least 3%, at least 4%, at least about 5%, at
least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at
least about 10%, at least 10%, at least 15%, at least 20%, at least
25%, or more. In certain embodiments of the third embodiment, the
improvement in rolling resistance (as measured by tan .delta. at
60.degree. C.) is at least 3% to about 10%, at least 3% to 15%, at
least 3% to 20%, or at least 3% to 25%.
Although the improvements in tire performance are described above
with respect to the methods of the third embodiment, it should be
understood that certain embodiments of the rubber compositions of
the first and second embodiments disclosed herein can also exhibit
similar or equivalent improvements in tire performance properties.
Accordingly, the above discussion of improvements in properties
such as E' at 30.degree. C. and tan .delta. at 0, 30 and 60.degree.
C. should be understood to be equally applicable to certain
embodiments of the rubber compositions of the first and second
embodiments.
EXAMPLES
The following examples illustrate specific and exemplary
embodiments and/or features of the embodiments of the present
disclosure. The examples are provided solely for the purposes of
illustration and should not be construed as limitations of the
present disclosure. Numerous variations over these specific
examples are possible without departing from the spirit and scope
of the presently disclosed embodiments. It should specifically be
understood that the saturated triglyceride components utilized in
the examples can be utilized with rubbers, fillers, and other
ingredients which differ in amount, composition, or both from those
used in the examples (i.e., as fully disclosed in the preceding
paragraphs). Moreover, saturated triglyceride components can be
utilized in amounts, relative amounts, from sources, and having
properties (e.g., a different melting point) that differ from those
used in the examples (i.e., as fully disclosed in the preceding
paragraphs).
Examples 1-4
In Examples 1-4, rubber compositions were prepared using
combinations of three conjugated diene-containing polymers and
copolymers, along with carbon black and silica as reinforcing
fillers and either low PCA petroleum oil, soy oil, or a saturated
triglyceride component as well as the additional ingredients
appearing in Table 1. Examples 3 and 4 are provided as working
examples of the present disclosure and each utilize a saturated
triglyceride component. Examples 1 and 2 are comparative examples
which lack any saturated triglyceride component but instead include
an equivalent amount of either low PCA petroleum oil (Example 1) or
soy oil (Example 2). The saturated triglyceride components used
were obtained from Cargill, Incorporated and are sold under the
Agri-Pure.RTM. tradename. The saturated triglyceride component used
in Example 3 was designated AP-660 and described by its supplier as
having a melting point of 64.degree. C. The saturated triglyceride
component used in Example 4 was designated AP-660-50M and described
by its supplier as having a melting point of 43.degree. C. The
rubber compositions were prepared in a three stage mixing process
(i.e., two master-batch stages, and final batch) according to the
formulations shown in Table 1. The amount of each ingredient used
is reported as parts per hundred rubber (phr). The mixing process
used for these formulations is outlined in Table 2 below. Each of
Examples 3 and 4 should be understood as containing 15 phr of
saturated triglyceride component, with the stearic acid of the
vulcanization activator #1 and the processing aid comprising zinc
salts of fatty acids not being considered to constitute or comprise
any portion of a saturated triglyceride component.
TABLE-US-00001 TABLE 1 Sample # 1 2 (Control) (Control) 3 4
Master-Batch First non-productive Styrene-butadiene copolymer 50 50
50 50 Natural rubber 10 10 10 10 Polybutadiene 40 40 40 40 Carbon
black (N134) 15 15 15 15 Silica 36 36 36 36 Silane 2.8 2.8 2.8 2.8
Low PCA oil 15 0 0 0 Soy oil 0 15 0 0 Saturated triglyceride 0 0 15
0 component #1 Saturated triglyceride 0 0 0 15 component #2
Vulcanization activator #1 2 2 2 2 (stearic acid) Processing
aid.sup.1 5 5 5 5 Second non-productive stage Silica 24 24 24 24
Silane 1.9 1.9 1.9 1.9 Antioxidant 1 1 1 1 Final Batch Vulcanizing
agent 1.85 1.85 1.85 1.85 Vulcanization activator #2 2 2 2 2
Vulcanizing accelerators 3.7 3.7 3.7 3.7 Total phr 210.25 210.25
210.25 210.25 .sup.1Processing aid comprising zinc salts of fatty
acids.
TABLE-US-00002 TABLE 2 Mixing Parameters Stage Time Condition
Masterbatch 0 seconds Charge polymers Stage 1 (initial 30 seconds
Charge ingredients as indicated in Table 1, increase temp:
65.degree. C., rotor to 75 rpm rotor rpm Drop based on max
temperature of 311.degree. F. (155.degree. C.) started at 65)
Masterbatch 0 seconds Charge additional ingredients listed under
Secondary Stage 2 (initial Masterbatch in Table 1. temp: 65.degree.
C., Drop based on max temperature of 311.degree. F. (155.degree.
C.) rotor rpm started at 65) Final Batch 0 seconds Charge Remill
Stage (initial 0 seconds Charge curatives temp: 65.degree. C., Drop
based on max temperature of 210.degree. F. (99.degree. C.) rotor
rpm at 65)
After curing at 170.degree. C. for 15 minutes, each of the rubber
compositions was tested for tensile properties. Results are shown
in Table 3 below wherein the abbreviation E' is used for dynamic
storage modulus, which provides a measure of the hardness of the
rubber composition; steering stability on a dry road surface (dry
performance) is generally impacted by E' with higher values
preferred. An improvement in E' at 30.degree. C. can, thus, be
understood as indicative of an improvement in handling when the
rubber composition is incorporated into a tire tread. The index
values listed in Table 3 were determined by comparing the value for
the formulation according to the present disclosure with the
respective value for control example 1 (i.e., dividing the test
value for example 2, 3 or 4 by the value for example 1).
Tensile mechanical properties of the samples were determined
following the guidelines, but not restricted to, the standard
procedure described in ASTM D-412, using dumbbell-shaped samples
with a cross-section dimension of 4 mm in width and 1.9 mm in
thickness at the center. Specimens were strained at a constant rate
and the resulting force was recorded as a function of extension
(strain). Force readings are shown in the Tables below as
engineering-stresses by reference to the original cross-sectional
area of the test piece. The specimens were tested at 25.degree. C.
unless indicated to the contrary.
The viscoelastic temperature sweep for the tan .delta. measurements
was conducted using a dynamic mechanical thermal spectrometer
(Eplexor.RTM. 500N from Gabo Qualimeter Testanlagen GmbH of Ahiden,
Germany) under the following conditions: measurement mode: tensile
test mode, measuring frequency: 52 Hz, applying 0.2% strain from 50
to -5.degree. C. and 1% strain from -5 to 65.degree. C., measuring
temperatures (0.degree. C., 30.degree. C. and 60.degree. C.),
sample shape: 4.75 mm wide.times.29 mm long.times.2.0 mm thick. A
rubber composition's tan .delta. at 0.degree. C. is indicative of
its wet traction when incorporated into a tire tread, its tan
.delta. at 30.degree. C. is indicative of its dry traction when
incorporated into a tire tread and its tan .delta. at 60.degree. C.
is indicative of its rolling resistance when incorporated into a
tire tread. Higher values of tan .delta. at 0.degree. C. and
30.degree. C. are beneficial (indicating improved wet and dry
traction) whereas lower values of tan .delta. at 60.degree. C. are
beneficial (indicating reduced rolling resistance which equates to
improved fuel economy).
The viscosities disclosed herein are real dynamic viscosities
determined using an Alpha Technologies RPA (Rubber Process
Analyzer) instrument which is rotorless.
Measurements were made following the guidance of, but not strictly
according to ASTM D 6204. In accordance with ASTM D 6204, a three
point frequency sweep was conducted. The rubber compositions were
pre-heated for 1 minute at 130.degree. C. In accordance with the
ASTM procedure, strain sweep was conducted at 130.degree. C.,
strain at 100 percent, and 1 Hz were conducted. The viscosity data
reported is from a run conducted at 266.degree. F., G' at 0.2
minutes.
TABLE-US-00003 TABLE 3 Sample # 1 2 (Control) (Control) 3 4 E' at
30.degree. C. 1.00 0.92 1.95 1.17 Indexed tan .delta. at 0.degree.
C. 1.00 1.02 1.07 1.06 Indexed tan .delta. at 30.degree. C. 1.00
1.04 1.10 1.05 Indexed tan .delta. at 60.degree. C. 1.00 1.04 1.06
0.92 Indexed viscosity 1.00 0.92 0.95 0.94
As can be seen from the data of Table 3, E' at 30.degree. C. is
improved (higher) for Examples 3 and 4 as compared to control
Example 1. A larger relative improvement in E' at 30.degree. C. was
exhibited in the rubber composition having the higher melting point
(64.degree. C.) saturated triglyceride component (Example 3). Both
examples 3 and 4 exhibited an improvement (increase) in tan .delta.
at 0.degree. C. and at 30.degree. C. as compared to control Example
1. Likewise, both example 3 and 4 exhibited a decrease in viscosity
as compared to control Example 1. The rubber composition having the
lower melting point saturated triglyceride component (43.degree.
C.) exhibited an improvement (decrease) in tan .delta. at
60.degree. C. as compared to control Example 1 whereas the rubber
composition having the higher melting point triglyceride component
(64.degree. C.) did not exhibit any improvement but instead
exhibited an increase in its value of tan .delta. at 60.degree.
C.
Graphs showing plots of E' and tan .delta. values over a
temperature range of 0 to about 60.degree. C. are included as FIGS.
1 and 2, respectively. As can be seen from FIG. 1, the rubber
composition having the higher melting point (64.degree. C.)
saturated triglyceride component (Example 3) exhibited a mostly
consistently higher E' than control Example 1 until exhibiting a
steeper decrease around 45-50.degree. C. which led to E' at about
65.degree. C. being at or below the E' for control Example 1. As
can also be seen from FIG. 1, the rubber composition having the
lower melting point (43.degree. C.) saturated triglyceride
component (Example 4) exhibited a mostly consistently higher E'
than control Example 1 until exhibiting a steeper decrease around
15-20.degree. C. which led to E' at about 40.degree. C. and higher
being at or below the E' for control Example 1. As can be seen from
FIG. 2, the rubber composition having the higher melting point
(64.degree. C.) saturated triglyceride component (Example 3)
exhibited a higher tan .delta. than control Example 1 until
exhibiting a sharper decrease around 55.degree. C. which led to its
tan .delta. above about 65.degree. C. being at or below the E' for
control Example 1. As can also be seen from FIG. 2, the rubber
composition having the lower melting point (43.degree. C.)
saturated triglyceride component (Example 4) exhibited a higher tan
.delta. than control Example 1 until decreasing to below the tan
.delta. for the control Example 1 at just over 40.degree. C. As
shown by the plots in FIGS. 1 and 2 it was unexpectedly discovered
that it is possible to control the inflection point at which E' or
tan .delta. intersects with the control value by changing the
melting point of the saturated triglyceride component.
This application discloses several numerical range limitations that
support any range within the disclosed numerical ranges, even
though a precise range limitation is not stated verbatim in the
specification, because the embodiments of the compositions and
methods disclosed herein could be practiced throughout the
disclosed numerical ranges. With respect to the use of
substantially any plural or singular terms herein, those having
skill in the art can translate from the plural to the singular or
from the singular to the plural as is appropriate to the context or
application. The various singular or plural permutations may be
expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general,
terms used herein, and especially in the appended claims are
generally intended as "open" terms. For example, the term
"including" should be interpreted as "including but not limited
to," the term "having" should be interpreted as "having at least,"
the term "includes" should be interpreted as "includes but is not
limited to." It will be further understood by those within the art
that if a specific number of an introduced claim recitation is
intended, such an intent will be explicitly recited in the claim,
and in the absence of such recitation no such intent is present.
For example, as an aid to understanding, the following appended
claims may contain usage of the introductory phrases "at least one"
and "one or more" to introduce claim recitations. However, the use
of such phrases should not be construed to imply that the
introduction of a claim recitation by the indefinite articles "a"
or "an" limits any particular claim containing such introduced
claim recitation to inventions containing only one such recitation,
even when the same claim includes the introductory phrases "one or
more" or "at least one" and indefinite articles such as "a" or "an"
(e.g., "a" or "an" should typically be interpreted to mean "at
least one" or "one or more"); the same holds true for the use of
definite articles used to introduce claim recitations. In addition,
even if a specific number of an introduced claim recitation is
explicitly recited, those skilled in the art will recognize that
such recitation should typically be interpreted to mean at least
the recited number (e.g., the bare recitation of "two recitations,"
without other modifiers, typically means at least two recitations,
or two or more recitations). Furthermore, in those instances where
a convention analogous to "at least one of A, B, and C, etc." is
used, in general such a construction is intended in the sense one
having skill in the art would understand the convention (e.g., "a
system having at least one of A, B, and C" would include but not be
limited to systems that have A alone, B alone, C alone, A and B
together, A and C together, B and C together, and/or A, B, and C
together, etc.). It will be further understood by those within the
art that virtually any disjunctive word or phrase presenting two or
more alternative terms, whether in the description, claims, or
drawings, should be understood to contemplate the possibilities of
including one of the terms, either of the terms, or both terms. For
example, the phrase "A or B" will be understood to include the
possibilities of "A" or "B" or "A and B."
All references, including but not limited to patents, patent
applications, and non-patent literature are hereby incorporated by
reference herein in their entirety.
While various aspects and embodiments of the compositions and
methods have been disclosed herein, other aspects and embodiments
will be apparent to those skilled in the art. The various aspects
and embodiments disclosed herein are for purposes of illustration
and are not intended to be limiting, with the true scope and spirit
being indicated by the claims.
* * * * *